1 /*** 2 This file is part of avahi. 3 4 avahi is free software; you can redistribute it and/or modify it 5 under the terms of the GNU Lesser General Public License as 6 published by the Free Software Foundation; either version 2.1 of the 7 License, or (at your option) any later version. 8 9 avahi is distributed in the hope that it will be useful, but WITHOUT 10 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 11 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General 12 Public License for more details. 13 14 You should have received a copy of the GNU Lesser General Public 15 License along with avahi; if not, write to the Free Software 16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 17 USA. 18 ***/ 19 20 #ifdef HAVE_CONFIG_H 21 #include <config.h> 22 #endif 23 24 #include <errno.h> 25 #include <string.h> 26 #include <unistd.h> 27 #include <stdlib.h> 28 #include <netinet/in.h> 29 30 #include "avahi-common/avahi-malloc.h" 31 #include <avahi-common/error.h> 32 #include <avahi-common/timeval.h> 33 34 #include "internal.h" 35 #include "browse.h" 36 #include "socket.h" 37 #include "log.h" 38 #include "hashmap.h" 39 #include "wide-area.h" 40 #include "addr-util.h" 41 #include "rr-util.h" 42 43 #define CACHE_ENTRIES_MAX 500 44 45 typedef struct AvahiWideAreaCacheEntry AvahiWideAreaCacheEntry; 46 47 struct AvahiWideAreaCacheEntry { 48 AvahiWideAreaLookupEngine *engine; 49 50 AvahiRecord *record; 51 struct timeval timestamp; 52 struct timeval expiry; 53 54 AvahiTimeEvent *time_event; 55 56 AVAHI_LLIST_FIELDS(AvahiWideAreaCacheEntry, by_key); 57 AVAHI_LLIST_FIELDS(AvahiWideAreaCacheEntry, cache); 58 }; 59 60 struct AvahiWideAreaLookup { 61 AvahiWideAreaLookupEngine *engine; 62 int dead; 63 64 uint32_t id; /* effectively just an uint16_t, but we need it as an index for a hash table */ 65 AvahiTimeEvent *time_event; 66 67 AvahiKey *key, *cname_key; 68 69 int n_send; 70 AvahiDnsPacket *packet; 71 72 AvahiWideAreaLookupCallback callback; 73 void *userdata; 74 75 AvahiAddress dns_server_used; 76 77 AVAHI_LLIST_FIELDS(AvahiWideAreaLookup, lookups); 78 AVAHI_LLIST_FIELDS(AvahiWideAreaLookup, by_key); 79 }; 80 81 struct AvahiWideAreaLookupEngine { 82 AvahiServer *server; 83 84 int fd_ipv4, fd_ipv6; 85 AvahiWatch *watch_ipv4, *watch_ipv6; 86 87 uint16_t next_id; 88 89 /* Cache */ 90 AVAHI_LLIST_HEAD(AvahiWideAreaCacheEntry, cache); 91 AvahiHashmap *cache_by_key; 92 unsigned cache_n_entries; 93 94 /* Lookups */ 95 AVAHI_LLIST_HEAD(AvahiWideAreaLookup, lookups); 96 AvahiHashmap *lookups_by_id; 97 AvahiHashmap *lookups_by_key; 98 99 int cleanup_dead; 100 101 AvahiAddress dns_servers[AVAHI_WIDE_AREA_SERVERS_MAX]; 102 unsigned n_dns_servers; 103 unsigned current_dns_server; 104 }; 105 106 static AvahiWideAreaLookup* find_lookup(AvahiWideAreaLookupEngine *e, uint16_t id) { 107 AvahiWideAreaLookup *l; 108 int i = (int) id; 109 110 assert(e); 111 112 if (!(l = avahi_hashmap_lookup(e->lookups_by_id, &i))) 113 return NULL; 114 115 assert(l->id == id); 116 117 if (l->dead) 118 return NULL; 119 120 return l; 121 } 122 123 static int send_to_dns_server(AvahiWideAreaLookup *l, AvahiDnsPacket *p) { 124 AvahiAddress *a; 125 126 assert(l); 127 assert(p); 128 129 if (l->engine->n_dns_servers <= 0) 130 return -1; 131 132 assert(l->engine->current_dns_server < l->engine->n_dns_servers); 133 134 a = &l->engine->dns_servers[l->engine->current_dns_server]; 135 l->dns_server_used = *a; 136 137 if (a->proto == AVAHI_PROTO_INET) { 138 139 if (l->engine->fd_ipv4 < 0) 140 return -1; 141 142 return avahi_send_dns_packet_ipv4(l->engine->fd_ipv4, AVAHI_IF_UNSPEC, p, NULL, &a->data.ipv4, AVAHI_DNS_PORT); 143 144 } else { 145 assert(a->proto == AVAHI_PROTO_INET6); 146 147 if (l->engine->fd_ipv6 < 0) 148 return -1; 149 150 return avahi_send_dns_packet_ipv6(l->engine->fd_ipv6, AVAHI_IF_UNSPEC, p, NULL, &a->data.ipv6, AVAHI_DNS_PORT); 151 } 152 } 153 154 static void next_dns_server(AvahiWideAreaLookupEngine *e) { 155 assert(e); 156 157 e->current_dns_server++; 158 159 if (e->current_dns_server >= e->n_dns_servers) 160 e->current_dns_server = 0; 161 } 162 163 static void lookup_stop(AvahiWideAreaLookup *l) { 164 assert(l); 165 166 l->callback = NULL; 167 168 if (l->time_event) { 169 avahi_time_event_free(l->time_event); 170 l->time_event = NULL; 171 } 172 } 173 174 static void sender_timeout_callback(AvahiTimeEvent *e, void *userdata) { 175 AvahiWideAreaLookup *l = userdata; 176 struct timeval tv; 177 178 assert(l); 179 180 /* Try another DNS server after three retries */ 181 if (l->n_send >= 3 && avahi_address_cmp(&l->engine->dns_servers[l->engine->current_dns_server], &l->dns_server_used) == 0) { 182 next_dns_server(l->engine); 183 184 if (avahi_address_cmp(&l->engine->dns_servers[l->engine->current_dns_server], &l->dns_server_used) == 0) 185 /* There is no other DNS server, fail */ 186 l->n_send = 1000; 187 } 188 189 if (l->n_send >= 6) { 190 avahi_log_warn(__FILE__": Query timed out."); 191 avahi_server_set_errno(l->engine->server, AVAHI_ERR_TIMEOUT); 192 l->callback(l->engine, AVAHI_BROWSER_FAILURE, AVAHI_LOOKUP_RESULT_WIDE_AREA, NULL, l->userdata); 193 lookup_stop(l); 194 return; 195 } 196 197 assert(l->packet); 198 send_to_dns_server(l, l->packet); 199 l->n_send++; 200 201 avahi_time_event_update(e, avahi_elapse_time(&tv, 1000, 0)); 202 } 203 204 AvahiWideAreaLookup *avahi_wide_area_lookup_new( 205 AvahiWideAreaLookupEngine *e, 206 AvahiKey *key, 207 AvahiWideAreaLookupCallback callback, 208 void *userdata) { 209 210 struct timeval tv; 211 AvahiWideAreaLookup *l, *t; 212 uint8_t *p; 213 214 assert(e); 215 assert(key); 216 assert(callback); 217 assert(userdata); 218 219 l = avahi_new(AvahiWideAreaLookup, 1); 220 l->engine = e; 221 l->dead = 0; 222 l->key = avahi_key_ref(key); 223 l->cname_key = avahi_key_new_cname(l->key); 224 l->callback = callback; 225 l->userdata = userdata; 226 227 /* If more than 65K wide area quries are issued simultaneously, 228 * this will break. This should be limited by some higher level */ 229 230 for (;; e->next_id++) 231 if (!find_lookup(e, e->next_id)) 232 break; /* This ID is not yet used. */ 233 234 l->id = e->next_id++; 235 236 /* We keep the packet around in case we need to repeat our query */ 237 l->packet = avahi_dns_packet_new(0); 238 239 avahi_dns_packet_set_field(l->packet, AVAHI_DNS_FIELD_ID, (uint16_t) l->id); 240 avahi_dns_packet_set_field(l->packet, AVAHI_DNS_FIELD_FLAGS, AVAHI_DNS_FLAGS(0, 0, 0, 0, 1, 0, 0, 0, 0, 0)); 241 242 p = avahi_dns_packet_append_key(l->packet, key, 0); 243 assert(p); 244 245 avahi_dns_packet_set_field(l->packet, AVAHI_DNS_FIELD_QDCOUNT, 1); 246 247 if (send_to_dns_server(l, l->packet) < 0) { 248 avahi_log_error(__FILE__": Failed to send packet."); 249 avahi_dns_packet_free(l->packet); 250 avahi_key_unref(l->key); 251 if (l->cname_key) 252 avahi_key_unref(l->cname_key); 253 avahi_free(l); 254 return NULL; 255 } 256 257 l->n_send = 1; 258 259 l->time_event = avahi_time_event_new(e->server->time_event_queue, avahi_elapse_time(&tv, 500, 0), sender_timeout_callback, l); 260 261 avahi_hashmap_insert(e->lookups_by_id, &l->id, l); 262 263 t = avahi_hashmap_lookup(e->lookups_by_key, l->key); 264 AVAHI_LLIST_PREPEND(AvahiWideAreaLookup, by_key, t, l); 265 avahi_hashmap_replace(e->lookups_by_key, avahi_key_ref(l->key), t); 266 267 AVAHI_LLIST_PREPEND(AvahiWideAreaLookup, lookups, e->lookups, l); 268 269 return l; 270 } 271 272 static void lookup_destroy(AvahiWideAreaLookup *l) { 273 AvahiWideAreaLookup *t; 274 assert(l); 275 276 lookup_stop(l); 277 278 t = avahi_hashmap_lookup(l->engine->lookups_by_key, l->key); 279 AVAHI_LLIST_REMOVE(AvahiWideAreaLookup, by_key, t, l); 280 if (t) 281 avahi_hashmap_replace(l->engine->lookups_by_key, avahi_key_ref(l->key), t); 282 else 283 avahi_hashmap_remove(l->engine->lookups_by_key, l->key); 284 285 AVAHI_LLIST_REMOVE(AvahiWideAreaLookup, lookups, l->engine->lookups, l); 286 287 avahi_hashmap_remove(l->engine->lookups_by_id, &l->id); 288 avahi_dns_packet_free(l->packet); 289 290 if (l->key) 291 avahi_key_unref(l->key); 292 293 if (l->cname_key) 294 avahi_key_unref(l->cname_key); 295 296 avahi_free(l); 297 } 298 299 void avahi_wide_area_lookup_free(AvahiWideAreaLookup *l) { 300 assert(l); 301 302 if (l->dead) 303 return; 304 305 l->dead = 1; 306 l->engine->cleanup_dead = 1; 307 lookup_stop(l); 308 } 309 310 void avahi_wide_area_cleanup(AvahiWideAreaLookupEngine *e) { 311 AvahiWideAreaLookup *l, *n; 312 assert(e); 313 314 while (e->cleanup_dead) { 315 e->cleanup_dead = 0; 316 317 for (l = e->lookups; l; l = n) { 318 n = l->lookups_next; 319 320 if (l->dead) 321 lookup_destroy(l); 322 } 323 } 324 } 325 326 static void cache_entry_free(AvahiWideAreaCacheEntry *c) { 327 AvahiWideAreaCacheEntry *t; 328 assert(c); 329 330 if (c->time_event) 331 avahi_time_event_free(c->time_event); 332 333 AVAHI_LLIST_REMOVE(AvahiWideAreaCacheEntry, cache, c->engine->cache, c); 334 335 t = avahi_hashmap_lookup(c->engine->cache_by_key, c->record->key); 336 AVAHI_LLIST_REMOVE(AvahiWideAreaCacheEntry, by_key, t, c); 337 if (t) 338 avahi_hashmap_replace(c->engine->cache_by_key, avahi_key_ref(c->record->key), t); 339 else 340 avahi_hashmap_remove(c->engine->cache_by_key, c->record->key); 341 342 c->engine->cache_n_entries --; 343 344 avahi_record_unref(c->record); 345 avahi_free(c); 346 } 347 348 static void expiry_event(AvahiTimeEvent *te, void *userdata) { 349 AvahiWideAreaCacheEntry *e = userdata; 350 351 assert(te); 352 assert(e); 353 354 cache_entry_free(e); 355 } 356 357 static AvahiWideAreaCacheEntry* find_record_in_cache(AvahiWideAreaLookupEngine *e, AvahiRecord *r) { 358 AvahiWideAreaCacheEntry *c; 359 360 assert(e); 361 assert(r); 362 363 for (c = avahi_hashmap_lookup(e->cache_by_key, r->key); c; c = c->by_key_next) 364 if (avahi_record_equal_no_ttl(r, c->record)) 365 return c; 366 367 return NULL; 368 } 369 370 static void run_callbacks(AvahiWideAreaLookupEngine *e, AvahiRecord *r) { 371 AvahiWideAreaLookup *l; 372 373 assert(e); 374 assert(r); 375 376 for (l = avahi_hashmap_lookup(e->lookups_by_key, r->key); l; l = l->by_key_next) { 377 if (l->dead || !l->callback) 378 continue; 379 380 l->callback(e, AVAHI_BROWSER_NEW, AVAHI_LOOKUP_RESULT_WIDE_AREA, r, l->userdata); 381 } 382 383 if (r->key->clazz == AVAHI_DNS_CLASS_IN && r->key->type == AVAHI_DNS_TYPE_CNAME) { 384 /* It's a CNAME record, so we have to scan the all lookups to see if one matches */ 385 386 for (l = e->lookups; l; l = l->lookups_next) { 387 AvahiKey *key; 388 389 if (l->dead || !l->callback) 390 continue; 391 392 if ((key = avahi_key_new_cname(l->key))) { 393 if (avahi_key_equal(r->key, key)) 394 l->callback(e, AVAHI_BROWSER_NEW, AVAHI_LOOKUP_RESULT_WIDE_AREA, r, l->userdata); 395 396 avahi_key_unref(key); 397 } 398 } 399 } 400 } 401 402 static void add_to_cache(AvahiWideAreaLookupEngine *e, AvahiRecord *r) { 403 AvahiWideAreaCacheEntry *c; 404 int is_new; 405 406 assert(e); 407 assert(r); 408 409 if ((c = find_record_in_cache(e, r))) { 410 is_new = 0; 411 412 /* Update the existing entry */ 413 avahi_record_unref(c->record); 414 } else { 415 AvahiWideAreaCacheEntry *t; 416 417 is_new = 1; 418 419 /* Enforce cache size */ 420 if (e->cache_n_entries >= CACHE_ENTRIES_MAX) 421 /* Eventually we should improve the caching algorithm here */ 422 goto finish; 423 424 c = avahi_new(AvahiWideAreaCacheEntry, 1); 425 c->engine = e; 426 c->time_event = NULL; 427 428 AVAHI_LLIST_PREPEND(AvahiWideAreaCacheEntry, cache, e->cache, c); 429 430 /* Add the new entry to the cache entry hash table */ 431 t = avahi_hashmap_lookup(e->cache_by_key, r->key); 432 AVAHI_LLIST_PREPEND(AvahiWideAreaCacheEntry, by_key, t, c); 433 avahi_hashmap_replace(e->cache_by_key, avahi_key_ref(r->key), t); 434 435 e->cache_n_entries ++; 436 } 437 438 c->record = avahi_record_ref(r); 439 440 gettimeofday(&c->timestamp, NULL); 441 c->expiry = c->timestamp; 442 avahi_timeval_add(&c->expiry, r->ttl * 1000000); 443 444 if (c->time_event) 445 avahi_time_event_update(c->time_event, &c->expiry); 446 else 447 c->time_event = avahi_time_event_new(e->server->time_event_queue, &c->expiry, expiry_event, c); 448 449 finish: 450 451 if (is_new) 452 run_callbacks(e, r); 453 } 454 455 static int map_dns_error(uint16_t error) { 456 static const int table[16] = { 457 AVAHI_OK, 458 AVAHI_ERR_DNS_FORMERR, 459 AVAHI_ERR_DNS_SERVFAIL, 460 AVAHI_ERR_DNS_NXDOMAIN, 461 AVAHI_ERR_DNS_NOTIMP, 462 AVAHI_ERR_DNS_REFUSED, 463 AVAHI_ERR_DNS_YXDOMAIN, 464 AVAHI_ERR_DNS_YXRRSET, 465 AVAHI_ERR_DNS_NXRRSET, 466 AVAHI_ERR_DNS_NOTAUTH, 467 AVAHI_ERR_DNS_NOTZONE, 468 AVAHI_ERR_INVALID_DNS_ERROR, 469 AVAHI_ERR_INVALID_DNS_ERROR, 470 AVAHI_ERR_INVALID_DNS_ERROR, 471 AVAHI_ERR_INVALID_DNS_ERROR, 472 AVAHI_ERR_INVALID_DNS_ERROR 473 }; 474 475 assert(error <= 15); 476 477 return table[error]; 478 } 479 480 static void handle_packet(AvahiWideAreaLookupEngine *e, AvahiDnsPacket *p) { 481 AvahiWideAreaLookup *l = NULL; 482 int i, r; 483 484 AvahiBrowserEvent final_event = AVAHI_BROWSER_ALL_FOR_NOW; 485 486 assert(e); 487 assert(p); 488 489 /* Some superficial validity tests */ 490 if (avahi_dns_packet_check_valid(p) < 0 || avahi_dns_packet_is_query(p)) { 491 avahi_log_warn(__FILE__": Ignoring invalid response for wide area datagram."); 492 goto finish; 493 } 494 495 /* Look for the lookup that issued this query */ 496 if (!(l = find_lookup(e, avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ID))) || l->dead) 497 goto finish; 498 499 /* Check whether this a packet indicating a failure */ 500 if ((r = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS) & 15) != 0 || 501 avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT) == 0) { 502 503 avahi_server_set_errno(e->server, r == 0 ? AVAHI_ERR_NOT_FOUND : map_dns_error(r)); 504 /* Tell the user about the failure */ 505 final_event = AVAHI_BROWSER_FAILURE; 506 507 /* We go on here, since some of the records contained in the 508 reply might be interesting in some way */ 509 } 510 511 /* Skip over the question */ 512 for (i = (int) avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_QDCOUNT); i > 0; i--) { 513 AvahiKey *k; 514 515 if (!(k = avahi_dns_packet_consume_key(p, NULL))) { 516 avahi_log_warn(__FILE__": Wide area response packet too short or invalid while reading question key. (Maybe a UTF-8 problem?)"); 517 avahi_server_set_errno(e->server, AVAHI_ERR_INVALID_PACKET); 518 final_event = AVAHI_BROWSER_FAILURE; 519 goto finish; 520 } 521 522 avahi_key_unref(k); 523 } 524 525 /* Process responses */ 526 for (i = (int) avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT) + 527 (int) avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_NSCOUNT) + 528 (int) avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ARCOUNT); i > 0; i--) { 529 530 AvahiRecord *rr; 531 532 if (!(rr = avahi_dns_packet_consume_record(p, NULL))) { 533 avahi_log_warn(__FILE__": Wide area response packet too short or invalid while reading response record. (Maybe a UTF-8 problem?)"); 534 avahi_server_set_errno(e->server, AVAHI_ERR_INVALID_PACKET); 535 final_event = AVAHI_BROWSER_FAILURE; 536 goto finish; 537 } 538 539 add_to_cache(e, rr); 540 avahi_record_unref(rr); 541 } 542 543 finish: 544 545 if (l && !l->dead) { 546 if (l->callback) 547 l->callback(e, final_event, AVAHI_LOOKUP_RESULT_WIDE_AREA, NULL, l->userdata); 548 549 lookup_stop(l); 550 } 551 } 552 553 static void socket_event(AVAHI_GCC_UNUSED AvahiWatch *w, int fd, AVAHI_GCC_UNUSED AvahiWatchEvent events, void *userdata) { 554 AvahiWideAreaLookupEngine *e = userdata; 555 AvahiDnsPacket *p = NULL; 556 557 if (fd == e->fd_ipv4) 558 p = avahi_recv_dns_packet_ipv4(e->fd_ipv4, NULL, NULL, NULL, NULL, NULL); 559 else { 560 assert(fd == e->fd_ipv6); 561 p = avahi_recv_dns_packet_ipv6(e->fd_ipv6, NULL, NULL, NULL, NULL, NULL); 562 } 563 564 if (p) { 565 handle_packet(e, p); 566 avahi_dns_packet_free(p); 567 } 568 } 569 570 AvahiWideAreaLookupEngine *avahi_wide_area_engine_new(AvahiServer *s) { 571 AvahiWideAreaLookupEngine *e; 572 573 assert(s); 574 575 e = avahi_new(AvahiWideAreaLookupEngine, 1); 576 e->server = s; 577 e->cleanup_dead = 0; 578 579 /* Create sockets */ 580 e->fd_ipv4 = s->config.use_ipv4 ? avahi_open_unicast_socket_ipv4() : -1; 581 e->fd_ipv6 = s->config.use_ipv6 ? avahi_open_unicast_socket_ipv6() : -1; 582 583 if (e->fd_ipv4 < 0 && e->fd_ipv6 < 0) { 584 avahi_log_error(__FILE__": Failed to create wide area sockets: %s", strerror(errno)); 585 586 if (e->fd_ipv6 >= 0) 587 close(e->fd_ipv6); 588 589 if (e->fd_ipv4 >= 0) 590 close(e->fd_ipv4); 591 592 avahi_free(e); 593 return NULL; 594 } 595 596 /* Create watches */ 597 598 e->watch_ipv4 = e->watch_ipv6 = NULL; 599 600 if (e->fd_ipv4 >= 0) 601 e->watch_ipv4 = s->poll_api->watch_new(e->server->poll_api, e->fd_ipv4, AVAHI_WATCH_IN, socket_event, e); 602 if (e->fd_ipv6 >= 0) 603 e->watch_ipv6 = s->poll_api->watch_new(e->server->poll_api, e->fd_ipv6, AVAHI_WATCH_IN, socket_event, e); 604 605 e->n_dns_servers = e->current_dns_server = 0; 606 e->next_id = (uint16_t) rand(); 607 608 /* Initialize cache */ 609 AVAHI_LLIST_HEAD_INIT(AvahiWideAreaCacheEntry, e->cache); 610 e->cache_by_key = avahi_hashmap_new((AvahiHashFunc) avahi_key_hash, (AvahiEqualFunc) avahi_key_equal, (AvahiFreeFunc) avahi_key_unref, NULL); 611 e->cache_n_entries = 0; 612 613 /* Initialize lookup list */ 614 e->lookups_by_id = avahi_hashmap_new((AvahiHashFunc) avahi_int_hash, (AvahiEqualFunc) avahi_int_equal, NULL, NULL); 615 e->lookups_by_key = avahi_hashmap_new((AvahiHashFunc) avahi_key_hash, (AvahiEqualFunc) avahi_key_equal, (AvahiFreeFunc) avahi_key_unref, NULL); 616 AVAHI_LLIST_HEAD_INIT(AvahiWideAreaLookup, e->lookups); 617 618 return e; 619 } 620 621 void avahi_wide_area_engine_free(AvahiWideAreaLookupEngine *e) { 622 assert(e); 623 624 avahi_wide_area_clear_cache(e); 625 626 while (e->lookups) 627 lookup_destroy(e->lookups); 628 629 avahi_hashmap_free(e->cache_by_key); 630 avahi_hashmap_free(e->lookups_by_id); 631 avahi_hashmap_free(e->lookups_by_key); 632 633 if (e->watch_ipv4) 634 e->server->poll_api->watch_free(e->watch_ipv4); 635 636 if (e->watch_ipv6) 637 e->server->poll_api->watch_free(e->watch_ipv6); 638 639 if (e->fd_ipv6 >= 0) 640 close(e->fd_ipv6); 641 642 if (e->fd_ipv4 >= 0) 643 close(e->fd_ipv4); 644 645 avahi_free(e); 646 } 647 648 void avahi_wide_area_clear_cache(AvahiWideAreaLookupEngine *e) { 649 assert(e); 650 651 while (e->cache) 652 cache_entry_free(e->cache); 653 654 assert(e->cache_n_entries == 0); 655 } 656 657 void avahi_wide_area_set_servers(AvahiWideAreaLookupEngine *e, const AvahiAddress *a, unsigned n) { 658 assert(e); 659 660 if (a) { 661 for (e->n_dns_servers = 0; n > 0 && e->n_dns_servers < AVAHI_WIDE_AREA_SERVERS_MAX; a++, n--) 662 if ((a->proto == AVAHI_PROTO_INET && e->fd_ipv4 >= 0) || (a->proto == AVAHI_PROTO_INET6 && e->fd_ipv6 >= 0)) 663 e->dns_servers[e->n_dns_servers++] = *a; 664 } else { 665 assert(n == 0); 666 e->n_dns_servers = 0; 667 } 668 669 e->current_dns_server = 0; 670 671 avahi_wide_area_clear_cache(e); 672 } 673 674 void avahi_wide_area_cache_dump(AvahiWideAreaLookupEngine *e, AvahiDumpCallback callback, void* userdata) { 675 AvahiWideAreaCacheEntry *c; 676 677 assert(e); 678 assert(callback); 679 680 callback(";; WIDE AREA CACHE ;;; ", userdata); 681 682 for (c = e->cache; c; c = c->cache_next) { 683 char *t = avahi_record_to_string(c->record); 684 callback(t, userdata); 685 avahi_free(t); 686 } 687 } 688 689 unsigned avahi_wide_area_scan_cache(AvahiWideAreaLookupEngine *e, AvahiKey *key, AvahiWideAreaLookupCallback callback, void *userdata) { 690 AvahiWideAreaCacheEntry *c; 691 AvahiKey *cname_key; 692 unsigned n = 0; 693 694 assert(e); 695 assert(key); 696 assert(callback); 697 698 for (c = avahi_hashmap_lookup(e->cache_by_key, key); c; c = c->by_key_next) { 699 callback(e, AVAHI_BROWSER_NEW, AVAHI_LOOKUP_RESULT_WIDE_AREA|AVAHI_LOOKUP_RESULT_CACHED, c->record, userdata); 700 n++; 701 } 702 703 if ((cname_key = avahi_key_new_cname(key))) { 704 705 for (c = avahi_hashmap_lookup(e->cache_by_key, cname_key); c; c = c->by_key_next) { 706 callback(e, AVAHI_BROWSER_NEW, AVAHI_LOOKUP_RESULT_WIDE_AREA|AVAHI_LOOKUP_RESULT_CACHED, c->record, userdata); 707 n++; 708 } 709 710 avahi_key_unref(cname_key); 711 } 712 713 return n; 714 } 715 716 int avahi_wide_area_has_servers(AvahiWideAreaLookupEngine *e) { 717 assert(e); 718 719 return e->n_dns_servers > 0; 720 } 721 722 723 724
